Fin Whales' Big Gulp

Fin Whales' Big Gulp

Article excerpt

Some baleen whales, in their powerful feeding lunges, can gulp a volume of water equal to a school bus, according to new calculations by biologists at the University of British Columbia and the University of California (UC), Berkeley. The findings appear in the journal Marine Ecology Progress Series.

These big gulps more than double the whale's size; at least for the few seconds it takes for the whale to squeeze the water out through its rack of baleen filters to capture tasty shrimp-like krill.

Researchers focused on the fin whale (Balaenoptera physalus), a large filter-feeding whale closely related to the blue and humpback whales, all of which are classified as rorquals. Up to 88 feet in length, these massive whales, second only to the blue whale in size, are known to feed in a series of lunges, each lasting about 6 to 10 seconds, in which they fill their mouths with krill-laden ocean water and then strain out the krill.

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"The scale of this activity almost defies imagination," says Nicholas D. Pyenson, a UC Berkeley graduate student in the Department of Integrative Biology and the Museum of Paleontology. The lunge carries the fin whale some 35 feet.

All of this happens under water, Pyenson explains, which makes studying the mechanics of these feeding lunges difficult. In the past decade, however, critter cams attached to whales via suction cups have provided video and audio of feeding whales, while digital tags have provided information on speed, body orientation, and swimming strokes. …